Flame-retardant B1-level fire-resistant cable special for metro

Abstract

The invention discloses a special flame-retardant B1-level fire-resistant cable for metros, and particularly relates to the technical field of cables, the special flame-retardant B1-level fire-resistant cable comprises a cable body, the cable body comprises a plurality of cable cores, each cable core is wrapped by an insulating layer, the insulating layers are wrapped by a flame-retardant filling layer, the flame-retardant filling layer is wrapped by a flame-retardant layer, and the flame-retardant layer is wrapped by a flame-retardant layer. And the outer sheath is wrapped outside the flame-retardant layer. According to the invention, through the arrangement of the first telescopic part, the second telescopic part and other structures, when the outer sheath is burnt out due to a fire disaster, the first limiting part and the second limiting part can be far away from each other and do not play a limiting role any more, and the plugging head which is not limited is pushed out of the plugging groove through the pushing plate, so that the separation between cables is completed, and the use is convenient. Fire is prevented from spreading to other non-damaged areas, overall damage is reduced, the power failure range can be minimized, power supply of non-fire areas is guaranteed, overall influence of fire on a subway system is reduced, property loss is reduced, and safety of passengers is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, and more specifically to a flame-retardant B1 grade fire-resistant cable specially used for subways. Background Art

[0002] "B1" in cable models usually represents B1-grade flame-retardant cable. B1-grade cable has good flame-retardant properties under fire conditions and can effectively prevent the spread of flames. Compared with other flame-retardant grades, B1-grade cable produces less smoke, less toxicity, less corrosiveness, and no burning drips during the combustion process, which can better ensure safety. As an important part of urban public transportation, cables are crucial to the safe, punctual and comfortable operation of the subway, the city's traffic order and the travel experience of citizens.

[0003] The Chinese patent application number CN202011621612.4 discloses a halogen-free, low-smoke, flame-retardant, Class B1 fireproof cable for subway and light rail transportation key projects, which includes an outer sheath, an armor layer, an inner lining layer and a wrapping layer from the outside to the inside, and the wrapping layer has multiple cable cores, and the cable core includes an insulating layer, a fire-resistant layer and a conductor from the outside to the inside; the insulating layer is made of cross-linked polyethylene; the fire-resistant layer is made of mica tape; the wrapping layer is a halogen-free high-resistance tape; the outer sheath is made of a halogen-free flame-retardant material; the armor layer is a copper tape; the wrapping layer also has a filling material, and the filling material is a halogen-free, low-smoke, high-flame-retardant PP rope. The cable in this application has a good flame-retardant and fire-extinguishing effect.

[0004] Although the above invention can play a flame retardant and fire extinguishing effect, when a serious fire occurs in the cable, the fire will still spread to other non-damaged areas, which will expand the scope of the fire, generate more smoke and flames, make it difficult for passengers to evacuate, and increase the risk of casualties. In addition, severely burned cables cannot be restored by simple repairs, and the cables need to be repaired and replaced. The repair and replacement procedures are relatively cumbersome, which will cause the subway line to partially or completely suspend operations, causing traffic inconvenience and increasing the burden on other means of transportation.

[0005] The present invention provides a flame-retardant B1 grade fire-resistant cable for subways, aiming to solve the problem that fire spreads to other non-damaged areas, causing difficulty in evacuating passengers and increasing the risk of casualties, and the cable maintenance and replacement procedures are cumbersome, causing traffic inconvenience and increasing the burden on other means of transportation. Summary of the invention

[0006] The purpose of the present invention is to provide a flame-retardant B1 grade fire-resistant cable for subways to solve the problems raised in the above background technology that the fire spreads to other non-damaged areas, causing difficulties in passenger evacuation and increasing the risk of casualties, and the cable maintenance and replacement procedures are cumbersome, causing traffic inconvenience and increasing the burden on other means of transportation.

[0007] To achieve the above object, the present invention provides the following technical solution: a flame-retardant B1 grade subway special fire-resistant cable, comprising a cable body, the cable body comprising a cable core, the cable core is provided with a plurality of cores, the plurality of cable cores are each wrapped with an insulating layer, the plurality of insulating layers are wrapped with a flame-retardant filling layer, the flame-retardant filling layer is wrapped with a flame-retardant layer, the flame-retardant layer is wrapped with an outer sheath, the two ends of the cable body are respectively provided with a first plug-in portion and a second plug-in portion, and two adjacent cable bodies can be butt-jointed; The first plug-in portion includes a plug connector opened at one end of the outer sheath, and the second plug-in portion includes a plug-in slot opened at the other end of the outer sheath away from the plug connector. A plurality of first limiting slots are equidistantly opened on the outer circumference of the plug connector, and a plurality of second limiting slots with the same number as the first limiting slots are equidistantly opened on the inner circumference of the plug-in slot. A first limiting piece is arranged in each of the first limiting slots, and a second limiting piece is arranged in each of the second limiting slots. When the plug connector of one of the cable bodies is fully inserted into the plug-in slot of the other cable body, the positions of the plurality of first limiting slots correspond to the positions of the plurality of second limiting slots, and the plurality of first limiting pieces and the plurality of second limiting pieces can be extended for limiting.

[0008] Preferably, a first mounting groove is provided on the outer circumference of the plug connector, a second mounting groove is provided on the inner circumference of the plug-in groove, a first airbag is embedded in the first mounting groove, a second airbag is embedded in the second mounting groove, and the inner walls of the first airbag and the second airbag are fixedly connected with a plurality of support rods distributed equidistantly. When the plug connector of one of the cable bodies is fully inserted into the plug-in groove of the other cable body, the positions of the first mounting groove and the second mounting groove correspond, and a seal can be formed between the first airbag and the second airbag.

[0009] Preferably, the first limiting member is located on one side inside the first limiting groove and is fixedly connected to a first sealing plate, and the first sealing plate is sealingly and slidingly connected in the first limiting groove, and the second limiting member is located on one side inside the second limiting groove and is fixedly connected to a second sealing plate, and the second sealing plate is sealingly and slidingly connected in the second limiting groove.

[0010] Preferably, a first telescopic groove is formed on a side of the first limiting member located outside the first limiting groove, and a first telescopic member is sealingly and slidably connected in the first telescopic groove; a second telescopic groove is formed on a side of the second limiting member located outside the second limiting groove, and a second telescopic member is sealingly and slidably connected in the second telescopic groove.

[0011] Preferably, the interior of the outer sheath is provided with sealing grooves whose number is the same as the number of the plug connectors and whose positions correspond to each other, and the plurality of sealing grooves are all connected to the interiors of the corresponding first limiting grooves and the corresponding second limiting grooves, and the plurality of sealing grooves are all connected to the first airbag and the second airbag.

[0012] Preferably, the first limiting member is located outside the first limiting groove and both sides along the length direction of the cable body are set as wedge-shaped surfaces, and the second limiting member is located outside the second limiting groove and both sides along the length direction of the cable body are set as wedge-shaped surfaces; A side of the first telescopic member located outside the first telescopic slot is configured as an arc surface, and a side of the second telescopic member located outside the second telescopic slot is configured as an arc surface.

[0013] Preferably, when the plug connector is inserted into the plug slot, the plug connector can cooperate with the wedge surface of the first limiting member and the arc surface of the first telescopic member so that the first limiting member slides inside the first limiting slot, and the first telescopic member slides inside the first telescopic slot, and the plug slot can cooperate with the wedge surface of the second limiting member and the arc surface of the second telescopic member so that the second limiting member slides inside the second limiting slot, and the second telescopic member slides inside the second telescopic slot.

[0014] Preferably, push grooves are provided at both ends of the flame retardant layer, and push plates are sealed and slidably connected in the two push grooves. Inert gas is filled between each push groove and the corresponding push plate, and inert gas is filled in each sealed groove. Inert gas is filled between each first telescopic groove and the corresponding first telescopic part, and inert gas is filled between each second telescopic groove and the corresponding second telescopic part, and the gas pressure of the inert gas in each sealed groove is greater than the gas of the expansion gas in the corresponding first telescopic groove and the corresponding second telescopic groove.

[0015] Preferably, when the plug connector is fully inserted into the plug slot, each of the first limiting members is staggered with the corresponding second limiting member, each of the first telescopic members can contact the corresponding second sealing plate surface, and each of the second telescopic members can contact the corresponding first sealing plate surface.

[0016] Preferably, a docking male connector is sleeved between one end of each cable core located inside the plug connector and the corresponding insulating layer, and a docking female connector is sleeved between one end of each cable core located inside the plug slot and the corresponding insulating layer, and the docking male connector can be inserted into the docking female connector for electrical connection.

[0017] Technical effects and advantages of the present invention: 1. The present invention arranges the first limiting member, the second limiting member and other structures. When the plug connector is fully inserted into the plug slot, the positions of the plurality of first limiting members and the plurality of second limiting members correspond to each other, so that the plurality of first limiting members and the corresponding second limiting members are arranged in a staggered manner. At this time, the plurality of first limiting members and the plurality of second limiting members can extend under the thrust of the inert gas. At this time, the plurality of first limiting members and the plurality of second limiting members can form a limit, so that the plug connector cannot be pulled out of the plug slot, and the maintenance and replacement work can be completed quickly, which can avoid expensive maintenance costs and downtime, reduce the time of subway service interruption, ensure the travel needs of passengers, reduce traffic pressure, maintain urban traffic order, and thus improve the overall operation efficiency; 2. The present invention adopts the arrangement of the first telescopic member, the second telescopic member and other structures. When a fire occurs and the outer sheath is burned, the inert gas in the multiple sealing grooves will leak and no longer provide thrust for the first limit member and the second limit member. The inert gas in the first telescopic groove and the second telescopic groove will expand and push the first telescopic member and the second telescopic member, so that the first limit member and the second limit member are separated from each other and no longer play a limiting role. The inert gas in the pushing groove will expand, and the plug connector that has been released from the limit will be pushed out of the plug slot through the pushing plate, thereby completing the separation between the cables, preventing the fire from spreading to other non-damaged areas, reducing the overall damage, minimizing the scope of power outages, ensuring the power supply in non-fire areas, reducing the overall impact of the fire on the subway system, thereby reducing property losses and ensuring the safety of passengers; 3. The present invention arranges the first airbag, the second airbag, the support rod and other structures. When a fire occurs and the outer sheath is burned, the first airbag and the second airbag will rupture. The inert gas ejected from the ruptured places of the first airbag and the second airbag will spray between the plug connector and the plug slot, playing a driving role, thereby further accelerating the separation of the cables. At the same time, the gas ejected after the rupture of the first airbag and the second airbag will spray to the two ends of the adjacent cable bodies during separation, reducing the oxygen concentration in the fire area, thereby inhibiting the spread of flames, so that the two ends of the adjacent cable bodies can be extinguished, further preventing the fire on the cable from spreading to the adjacent cables. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a cross-sectional view of the cable body structure of the present invention.

[0019] Figure 2It is a schematic structural diagram of the first plug-in portion of the present invention.

[0020] Figure 3 It is a schematic structural diagram of the second plug-in portion of the present invention.

[0021] Figure 4 This is a schematic diagram of the outer sheath structure of the present invention.

[0022] Figure 5 This is a schematic diagram of the cable body plug-in of the present invention.

[0023] Figure 6 This is a cross-sectional view of the internal structure of the cable body of the present invention.

[0024] Figure 7 For the present invention Figure 6 A-section structure enlarged view.

[0025] Figure 8 This is an exploded view of the partial structure of the first limiting member of the present invention.

[0026] Fig. 9 This is an exploded view of the partial structure of the second limiting member of the present invention.

[0027] Fig.10 It is a cross-sectional view of the first limiting member and the second limiting member in the matching state of the present invention.

[0028] Fig.11 It is a schematic diagram of the first airbag of the present invention.

[0029] Fig.12 It is a cross-sectional view of the internal structure of the first airbag of the present invention.

[0030] The accompanying drawings are marked as follows: 1. cable body; 11. cable core; 12. insulation layer; 13. flame retardant filling layer; 14. flame retardant layer; 15. outer sheath; 2. first plug-in part; 21. plug connector; 22. first limit groove; 23. first limit piece; 24. first mounting groove; 25. first air bag; 26. first sealing plate; 27. first telescopic groove; 28. first telescopic piece; 29. ​​docking male head; 3. second plug-in part; 31. plug-in groove; 32. second limit groove; 33. second limit piece; 34. second mounting groove; 35. second air bag; 36. second sealing plate; 37. second telescopic groove; 38. second telescopic piece; 39. docking female head; 4. support rod; 5. sealing groove; 6. push groove; 61. push plate. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Embodiment 1 Severely burned cables cannot be restored by simple repairs. They need to be repaired and replaced, and the repair and replacement procedures are rather cumbersome. This will cause the subway line to partially or completely suspend operations, causing traffic inconvenience and increasing the burden on other means of transportation.

[0033] refer to Figure 1 and Figure 5 A flame-retardant B1 grade fire-resistant cable for subway use according to an embodiment of the present invention comprises a cable body 1, wherein the cable body 1 comprises a cable core 11, wherein a plurality of cable cores 11 are provided, wherein each of the plurality of cable cores 11 is wrapped with an insulating layer 12, wherein each of the plurality of insulating layers 12 is wrapped with a flame-retardant filling layer 13, wherein the flame-retardant filling layer 13 is wrapped with a flame-retardant layer 14, wherein the flame-retardant layer 14 is wrapped with an outer sheath 15, wherein a first plug-in portion 2 and a second plug-in portion 3 are provided at both ends of the cable body 1, respectively, and two adjacent cable bodies 1 can be butt-jointed.

[0034] refer to Figure 1 and Figure 5 The first plug-in portion 2 includes a plug connector 21 provided at one end of the outer sheath 15, and the second plug-in portion 3 includes a plug-in slot 31 provided at the other end of the outer sheath 15 away from the plug connector 21. A plurality of first limiting slots 22 are equidistantly provided on the outer circumference of the plug connector 21, and a plurality of second limiting slots 32 are equidistantly provided on the inner circumference of the plug-in slot 31, and the same number as the first limiting slots 22 are equidistantly provided on the inner circumference of the plug-in slot 31. A first limiting member 23 is provided in each first limiting slot 22, and a second limiting member 33 is provided in each second limiting slot 32. When the plug connector 21 of one of the cable bodies 1 is fully inserted into the plug-in slot 31 of the other cable body 1, the positions of the plurality of first limiting slots 22 correspond to the positions of the plurality of second limiting slots 32, and the plurality of first limiting members 23 and the plurality of second limiting members 33 can be extended for limiting.

[0035] refer to Figure 7-10The first limiting member 23 is located on one side inside the first limiting groove 22 and is fixedly connected to a first sealing plate 26, and the first sealing plate 26 is sealingly and slidably connected to the first limiting groove 22. The second limiting member 33 is located on one side inside the second limiting groove 32 and is fixedly connected to a second sealing plate 36, and the second sealing plate 36 is sealingly and slidably connected to the second limiting groove 32. The outer sheath 15 is provided with sealing grooves 5 having the same number and corresponding positions as the plug connector 21. The multiple sealing grooves 5 are connected to the corresponding first limiting groove 22 and the corresponding second limiting groove 32. Each sealing groove 5 is filled with an inert gas. The first limiting member 23 is located outside the first limiting groove 22 and both sides along the length direction of the cable body 1 are set as wedge-shaped surfaces. The second limiting member 33 is located outside the second limiting groove 32 and both sides along the length direction of the cable body 1 are set as wedge-shaped surfaces.

[0036] refer to Figure 1 , Figure 2 and Figure 6 A docking male connector 29 is sleeved between one end of each cable core 11 located inside the plug connector 21 and the corresponding insulating layer 12, and a docking female connector 39 is sleeved between one end of each cable core 11 located inside the plug slot 31 and the corresponding insulating layer 12. The docking male connector 29 can be inserted into the docking female connector 39 for electrical connection.

[0037] When the plug connector 21 is inserted into the plug slot 31, the plug connector 21 can cooperate with the wedge-shaped surface of the first limiting member 23, so that the first limiting member 23 slides inside the first limiting slot 22, and the plug slot 31 can cooperate with the wedge-shaped surface of the second limiting member 33, so that the second limiting member 33 slides inside the second limiting slot 32.

[0038] When the plug connector 21 is fully inserted into the plug slot 31 , each first limiting member 23 and the corresponding second limiting member 33 are arranged alternately.

[0039] During specific use, when the cable is severely burned and needs to be repaired and replaced, the first plug-in portion 2 of one cable body 1 is positioned corresponding to the second plug-in portion 3 of the other cable body 1, the plug connector 21 is inserted into the plug slot 31, and the multiple docking male connectors 29 are inserted into the corresponding docking female connectors 30.

[0040] Since the sealing groove 5 is filled with inert gas, the plurality of sealing grooves 5 are connected with the interior of the corresponding first limiting groove 22 and the corresponding second limiting groove 32, so the first limiting member 23 and the second limiting member 33 are both in an extended state before plugging. In the process of inserting the plug connector 21 into the plug connector slot 31, the plug connector 21 can cooperate with the wedge-shaped surface of the first limiting member 23, so that the first limiting member 23 slides inside the first limiting groove 22 and compresses the inert gas in the sealing groove 5 through the first sealing plate 26. The plug connector slot 31 can cooperate with the wedge-shaped surface of the second limiting member 33, so that the second limiting member 33 slides inside the second limiting groove 32 and compresses the inert gas in the sealing groove 5 through the second sealing plate 36, so that the plug connector 21 can be smoothly inserted into the plug connector slot 31. When the plug connector 21 is fully inserted into the plug slot 31, Figure 7 and Fig.10 , which will make the positions of the multiple first limiting grooves 22 correspond to the positions of the multiple second limiting grooves 32, so that the multiple first limiting members 23 and the corresponding second limiting members 33 are staggered. At this time, the multiple first limiting members 23 and the multiple second limiting members 33 can be extended under the thrust of the inert gas. At this time, a limit can be formed between the multiple first limiting members 23 and the multiple second limiting members 33, so that the plug connector 21 cannot be pulled out of the plug slot 31, thereby quickly completing the maintenance and replacement work.

[0041] To sum up, through the arrangement of the first limit piece 23, the second limit piece 33 and other structures, when the plug connector 21 is fully inserted into the plug slot 31, the positions of the multiple first limit slots 22 and the multiple second limit slots 32 will correspond, so that the multiple first limit pieces 23 and the corresponding second limit pieces 33 are staggered. At this time, the multiple first limit pieces 23 and the multiple second limit pieces 33 can be extended under the thrust of the inert gas. At this time, a limit can be formed between the multiple first limit pieces 23 and the multiple second limit pieces 33, so that the plug connector 21 cannot be pulled out of the plug slot 31, and the maintenance and replacement work can be completed quickly, which can avoid expensive maintenance costs and downtime, reduce the time of subway service interruption, ensure the travel needs of passengers, reduce traffic pressure, maintain urban traffic order, and thus improve overall operational efficiency.

[0042] Embodiment 2 During actual use, when a serious fire occurs in the cable, the fire may still spread to other non-damaged areas, expanding the scope of the fire, generating more smoke and flames, making it difficult for passengers to evacuate and increasing the risk of casualties. Therefore, this embodiment improves the device described in the above embodiment.

[0043] refer to Figure 7-10The first limiting member 23 is provided with a first telescopic groove 27 on one side outside the first limiting groove 22, and a first telescopic member 28 is sealed and slidably connected in the first telescopic groove 27. The second limiting member 33 is provided with a second telescopic groove 37 on one side outside the second limiting groove 32, and a second telescopic member 38 is sealed and slidably connected in the second telescopic groove 37. The side of the first telescopic member 28 located outside the first telescopic groove 27 is set as an arc surface, and the side of the second telescopic member 38 located outside the second telescopic groove 37 is set as an arc surface.

[0044] refer to Figure 8 Both ends of the flame retardant layer 14 are provided with a pushing groove 6, and a pushing plate 61 is sealed and slidably connected in the two pushing grooves 6. An inert gas is filled between each pushing groove 6 and the corresponding pushing plate 61, and an inert gas is filled between each first telescopic groove 27 and the corresponding first telescopic member 28. An inert gas is filled between each second telescopic groove 37 and the corresponding second telescopic member 38, and the gas pressure of the inert gas in each sealing groove 5 is greater than the gas of the expansion gas in the corresponding first telescopic groove 27 and the corresponding second telescopic groove 37.

[0045] When the plug connector 21 is inserted into the interior of the plug-in slot 31, the plug connector 21 can cooperate with the wedge-shaped surface of the first limiting member 23 and the arc surface of the first telescopic member 28 to make the first limiting member 23 slide inside the first limiting slot 22, and the first telescopic member 28 slide inside the first telescopic slot 27. The plug-in slot 31 can cooperate with the wedge-shaped surface of the second limiting member 33 and the arc surface of the second telescopic member 38, so that the second limiting member 33 slides inside the second limiting slot 32, and the second telescopic member 38 slides inside the second telescopic slot 37.

[0046] When the plug connector 21 is fully inserted into the plug slot 31 , each first limit member 23 is staggered with the corresponding second limit member 33 , each first telescopic member 28 can contact the surface of the corresponding second sealing plate 36 , and each second telescopic member 38 can contact the surface of the corresponding first sealing plate 26 .

[0047] When in use, when the plug connector 21 is inserted into the plug slot 31, the plug connector 21 will preferentially cooperate with the wedge-shaped surface of the first limiting member 23, and the first telescopic member 28 will follow the first limiting member 23 to slide inside the first limiting slot 22, so that the plug connector 21 can cooperate with the arc surface of the first telescopic member 28 during further movement, thereby pushing the first telescopic member 28 to slide in the first telescopic slot 27 and compressing the inert gas in the first telescopic slot 27; The plug-in slot 31 will preferentially cooperate with the wedge-shaped surface of the second limiting member 33, and the second telescopic member 38 will follow the second limiting member 33 to slide inside the second limiting slot 32, so that the plug-in slot 31 can cooperate with the arc surface of the second telescopic member 38 during further movement, thereby pushing the second telescopic member 38 to slide in the second telescopic slot 37 and compressing the inert gas in the second telescopic slot 37, thereby not affecting the plug-in connection between the plug connector 21 and the plug-in slot 31.

[0048] When the plug connector 21 is fully inserted into the plug slot 31, so that the multiple first limit members 23 and the corresponding second limit members 33 are staggered, the multiple first telescopic members 28 can contact the surface of the corresponding second sealing plate 36 under the thrust of the inert gas in the corresponding first telescopic slot 27, and the multiple second telescopic members 38 can contact the surface of the corresponding first sealing plate 26 under the thrust of the inert gas in the second telescopic slot 37. Since the gas pressure of the inert gas in the multiple sealing slots 5 is greater than the gas pressure of the inert gas in the corresponding first telescopic slot 27 and the corresponding second telescopic slot 37, at this time, the first telescopic member 28 and the second telescopic member 38 cannot push the corresponding first limit member 23 and the corresponding second limit member 33 away from each other, and cannot release the limit between the first limit member 23 and the second limit member 33, which will not affect the docking between the cables.

[0049] At the same time, when the plug connector 21 is inserted into the plug slot 31, the positions of the two push slots 6 will correspond, and the two push plates 61 will be squeezed against each other, so that the two push plates 61 slide in the corresponding push slots 6 and compress the inert gas in the corresponding push slots 6.

[0050] When a fire occurs and the outer sheath 15 is burned, the inert gas in the multiple sealing grooves 5 will expand and leak. The leaked inert gas can extinguish the fire and reduce the spread of the fire. After the inert gas leaks, the pressure in the first limiting groove 22 and the second limiting groove 32 will disappear, and no thrust will be provided for the first limiting member 23 and the second limiting member 33. At this time, the inert gas in the first telescopic groove 27 and the second telescopic groove 37 will expand and push the first telescopic member 28 and the second telescopic member 38 back to the initial position. At the same time, the first telescopic member 28 and the second telescopic member 38 will push the first limiting member 23 and the second limiting member 33 away from each other. At this time, the wedges on the side where the first limiting member 23 and the second limiting member 33 are close to each other can cooperate, and the first limiting member 23 and the second limiting member 33 no longer play a limiting role.

[0051] At the same time, the inert gas in the push groove 6 will expand, causing the push plate 61 to extend, thereby pushing the unrestricted plug connector 21 out of the plug groove 31, thereby completing the separation between the cables, preventing the fire from spreading to other non-damaged areas, and reducing overall damage.

[0052] To sum up, through the arrangement of the first telescopic member 28, the second telescopic member 38 and other structures, when a fire occurs and the outer sheath 15 is burned, the inert gas in the multiple sealing grooves 5 will leak and no longer provide thrust for the first limit member 23 and the second limit member 33. The inert gas in the first telescopic groove 27 and the second telescopic groove 37 will expand and push the first telescopic member 28 and the second telescopic member 38, so that the first limit member 23 and the second limit member 33 are separated from each other and no longer play a limiting role. The inert gas in the pushing groove 6 will expand and push the released plug connector 21 out of the plug connector groove 31 through the pushing plate 61, thereby completing the separation between the cables, preventing the fire from spreading to other non-damaged areas, reducing the overall damage, minimizing the scope of power outages, ensuring the power supply in non-fire areas, reducing the overall impact of the fire on the subway system, thereby reducing property losses and ensuring the safety of passengers.

[0053] Embodiment 3 In order to further reduce the spread of fire, accelerate the separation between cables and improve the flame retardant and fire resistance effects.

[0054] refer to Figure 4 , Figure 7 , Fig.11 and Fig.12 A first mounting groove 24 is provided on the outer circumference of the plug connector 21, and a second mounting groove 34 is provided on the inner circumference of the plug slot 31. A first airbag 25 is embedded in the first mounting groove 24, and a second airbag 35 is embedded in the second mounting groove 34. The inner walls of the first airbag 25 and the second airbag 35 are fixedly connected with a plurality of support rods 4 distributed equidistantly. A plurality of sealing grooves 5 are connected with the first airbag 25 and the second airbag 35. When the plug connector 21 of one cable body 1 is fully inserted into the plug slot 31 of the other cable body 1, the positions of the first mounting groove 24 and the second mounting groove 34 correspond to each other, and a seal can be formed between the first airbag 25 and the second airbag 35.

[0055] In actual use, when the plug connector 21 is fully inserted into the plug slot 31, the first installation slot 24 will correspond to the position of the second installation slot 34, and the first airbag 25 and the second airbag 35 can expand and form a seal under the action of the inert gas in the multiple sealing grooves 5, thereby preventing moisture from entering the cable, avoiding the degradation of insulation performance and electrical failures caused by moisture, and at the same time protecting the cable from chemical corrosion and extending the service life of the cable.

[0056] When a fire occurs and the outer sheath 15 is burned, the inert gas in the multiple sealing grooves 5 will expand first, and the expanded inert gas will enter the first airbag 25 and the second airbag 35, causing the first airbag 25 and the second airbag 35 to further expand violently, causing a tear between the inner surface of the first airbag 25 and the second airbag 35 and the support rod 4, causing the first airbag 25 and the second airbag 35 to rupture, and at this time, the inert gas in the first airbag 25 and the second airbag 35 will spray out from the rupture. When the outer sheath 15 is burned and the inert gas in multiple sealing grooves 5 leaks, so that the first limit member 23 and the second limit member 33 no longer play a limiting role, the inert gas ejected from the rupture of the first airbag 25 and the second airbag 35 will be sprayed between the plug connector 21 and the plug slot 31, playing a driving role, thereby further accelerating the separation between the cables.

[0057] At the same time, the gas ejected after the first airbag 25 and the second airbag 35 rupture will spray toward the two ends of the adjacent cable bodies 1 when separated, thereby extinguishing the fire at both ends of the adjacent cable bodies 1 and further preventing the fire on the cable from spreading to the adjacent cables.

[0058] To summarize, through the arrangement of the first airbag 25, the second airbag 35, the support rod 4 and other structures, when a fire occurs and the outer sheath 15 is burned, the first airbag 25 and the second airbag 35 will rupture, and the inert gas ejected from the ruptured places of the first airbag 25 and the second airbag 35 will be sprayed between the plug connector 21 and the plug slot 31, playing a driving role, thereby further accelerating the separation between the cables. At the same time, the gas ejected after the rupture of the first airbag 25 and the second airbag 35 will be sprayed to the two ends of the adjacent cable bodies 1 during separation, reducing the oxygen concentration in the fire area, thereby suppressing the spread of the flame, so that the two ends of the adjacent cable bodies 1 can be extinguished, further preventing the fire on the cable from spreading to the adjacent cables.

[0059] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A flame-retardant B1 grade fire-resistant cable for subway use, comprising a cable body (1), characterized in that: The cable body (1) comprises a cable core (11), wherein a plurality of the cable cores (11) are provided, each of the plurality of cable cores (11) is wrapped with an insulating layer (12), each of the plurality of insulating layers (12) is wrapped with a flame retardant filling layer (13), each of the flame retardant filling layer (13) is wrapped with a flame retardant layer (14), and each of the flame retardant layer (14) is wrapped with an outer sheath (15), and a first plug-in portion (2) and a second plug-in portion (3) are provided at both ends of the cable body (1), respectively, and two adjacent cable bodies (1) can be butt-jointed; The first plug-in portion (2) comprises a plug connector (21) provided at one end of the outer sheath (15), the second plug-in portion (3) comprises a plug slot (31) provided at the other end of the outer sheath (15) away from the plug connector (21), a plurality of first limiting slots (22) being equidistantly provided on the outer circumference of the plug connector (21), and a plurality of second limiting slots (32) being equidistantly provided on the inner circumference of the plug slot (31) as many as the first limiting slots (22), each of the first limiting slots (31) having a plurality of first limiting slots (22) and a plurality of second limiting slots (32) being equidistantly provided on the inner circumference of the plug slot (31). A first limiting member (23) is provided in each slot (22), and a second limiting member (33) is provided in each second limiting slot (32). When the plug connector (21) of one of the cable bodies (1) is fully inserted into the plug connector slot (31) of another cable body (1), the positions of the plurality of first limiting slots (22) and the plurality of second limiting slots (32) correspond to each other, and the plurality of first limiting members (23) and the plurality of second limiting members (33) can be extended to perform limiting.

2. The flame-retardant B1 grade fire-resistant cable for subway use according to claim 1, characterized in that: A first mounting groove (24) is provided on the outer circumference of the plug connector (21), and a second mounting groove (34) is provided on the inner circumference of the plug slot (31). A first airbag (25) is embedded in the first mounting groove (24), and a second airbag (35) is embedded in the second mounting groove (34). The inner walls of the first airbag (25) and the second airbag (35) are fixedly connected to a plurality of support rods (4) distributed at equal intervals. When the plug connector (21) of one of the cable bodies (1) is fully inserted into the plug slot (31) of the other cable body (1), the first mounting groove (24) and the second mounting groove (34) are positioned correspondingly, and a seal can be formed between the first airbag (25) and the second airbag (35).

3. The flame-retardant B1 grade fire-resistant cable for subway use according to claim 2 is characterized in that: The first limiting member (23) is located at one side inside the first limiting groove (22) and is fixedly connected to a first sealing plate (26), and the first sealing plate (26) is sealingly and slidably connected in the first limiting groove (22), and the second limiting member (33) is located at one side inside the second limiting groove (32) and is fixedly connected to a second sealing plate (36), and the second sealing plate (36) is sealingly and slidably connected in the second limiting groove (32).

4. The flame-retardant B1 grade fire-resistant cable for subway use according to claim 3 is characterized by: The first limiting member (23) is provided with a first telescopic groove (27) on one side outside the first limiting groove (22), and a first telescopic member (28) is sealed and slidably connected inside the first telescopic groove (27). The second limiting member (33) is provided with a second telescopic groove (37) on one side outside the second limiting groove (32), and a second telescopic member (38) is sealed and slidably connected inside the second telescopic groove (37).

5. The flame-retardant B1 grade fire-resistant cable for subway use according to claim 4 is characterized in that: The outer sheath (15) is provided with sealing grooves (5) in the same number as the plug connector (21) and in corresponding positions, and the plurality of sealing grooves (5) are all in communication with the interior of the corresponding first limiting groove (22) and the corresponding second limiting groove (32), and the plurality of sealing grooves (5) are all in communication with the first airbag (25) and the second airbag (35).

6. The flame-retardant B1 grade fire-resistant cable for subway use according to claim 5, characterized in that: The first limiting member (23) is located outside the first limiting groove (22) and has wedge-shaped surfaces on both sides along the length direction of the cable body (1); the second limiting member (33) is located outside the second limiting groove (32) and has wedge-shaped surfaces on both sides along the length direction of the cable body (1); A side of the first telescopic member (28) located outside the first telescopic slot (27) is configured as an arc surface, and a side of the second telescopic member (38) located outside the second telescopic slot (37) is configured as an arc surface.

7. The flame-retardant B1 grade fire-resistant cable for subway use according to claim 6, characterized in that: When the plug connector (21) is inserted into the inserting slot (31), the plug connector (21) can cooperate with the wedge-shaped surface of the first limiting member (23) and the arc surface of the first telescopic member (28) so that the first limiting member (23) slides inside the first limiting slot (22), and the first telescopic member (28) slides inside the first telescopic slot (27); the inserting slot (31) can cooperate with the wedge-shaped surface of the second limiting member (33) and the arc surface of the second telescopic member (38), so that the second limiting member (33) slides inside the second limiting slot (32), and the second telescopic member (38) slides inside the second telescopic slot (37).

8. The flame-retardant B1 grade fire-resistant cable for subway use according to claim 7 is characterized in that: Both ends of the flame retardant layer (14) are provided with push grooves (6), and push plates (61) are sealed and slidably connected in the two push grooves (6). Inert gas is filled between each push groove (6) and the corresponding push plate (61), and inert gas is filled in each sealing groove (5). Inert gas is filled between each first telescopic groove (27) and the corresponding first telescopic member (28), and inert gas is filled between each second telescopic groove (37) and the corresponding second telescopic member (38), and the gas pressure of the inert gas in each sealing groove (5) is greater than the gas pressure of the expansion gas in the corresponding first telescopic groove (27) and the corresponding second telescopic groove (37).

9. The flame-retardant B1 grade fire-resistant cable for subway use according to claim 8, characterized in that: When the plug connector (21) is fully inserted into the plug slot (31), each of the first limiting members (23) and the corresponding second limiting members (33) are arranged in a staggered manner, each of the first telescopic members (28) can contact the surface of the corresponding second sealing plate (36), and each of the second telescopic members (38) can contact the surface of the corresponding first sealing plate (26).

10. The flame-retardant B1 grade fire-resistant cable for subway use according to claim 9, characterized in that: A male butt joint (29) is sleeved between one end of each cable core (11) located inside the plug connector (21) and the corresponding insulating layer (12), and a female butt joint (39) is sleeved between one end of each cable core (11) located inside the plug slot (31) and the corresponding insulating layer (12), and the male butt joint (29) can be inserted into the female butt joint (39) for electrical connection.

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